During the past year Phase II, a multivariant analysis to determine the relationship of birthweight as the dependent variable to a large number of antecedent (prenatal) independent variables, has been completed. The examination of a Birthweight Index derived from Phases I and II to determine its predictive value for birthweight-gestational age outcomes has been completed. A monograph is being prepared under personal services contracts with J.B. Hardy and E.D. Mellits.